Telephone



Dec. 17, 1929. CONT] 1,739,889

TELEPHONE Filed July 18, 1927 TRANSMITTER mvo RECEIVER j ANSMITTER AND Ti'lmsmrrren AND 7 Rscswsa Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE JAMES TIBURGE FELIX CONTI, OF PARIS, FRANCE, ASSIGNOR T RENE LEON JACQUES LAURENT DE LA VILLE LE ROULX, OF PARIS, FRANCE TELEPHONE Application filed July 18, 1927, Serial No. 206,611, and in France July 22, 1926.

cuit separation properly situated in order to allow the subscriber to lock his station so as to render impossible all demands for connection with the telephone exchange although he may receive the calls and talk with persons :5; who have asked to be connected from outside.

My invention may be executed in various manners and the annexed drawings show by way of example two very different modes of execution according as it is desired to place 6 the device upon the telephone itself or at an indefinite distance therefrom.

In the accompanying drawings, 1 shows diagrammatically a telephone plant comprising an ordinary central battery.

;- F ig. 2 represents diagrammatically a mode of construction of the device according to my invention operated from the call lever.

Fig. 3 represents diagrammatically a mode of execution of my invention comprising a my small apparatus connected to the line by means of a three-thread cable which may be placed at any point independently of the po sition of the telephone.

Figs. 4, 5, 6 and 7 are respectively a side iview, an end elevation, a plan view and end elevation, respectively, of an apparatus based on the diagram shown in Fig. 3.

Fig. 8 is a longitudinal view of a key designed for putting the telephone in its initial I position shown in Fig. 1.

All the subscribers stations of a telephone network with central battery may be illustrated by the diagram shown in Fig. 1 which comprises 1. A completely closed circuit ending at the incoming and outgoing telephone terminals A and B and comprising the transmitting and receiving apparatus T as well as the contacts of the movable lever L which close the circuit.

: 2. A circuit M N shunted upon the first,

separated by a condenser C and through the magnetic alarm S.

I will now describe by reference to the accompanying drawings two modes of execution of the arrangement of a telephone plant in ac cordance with my invention.

The mode of realization shown diagramiatically in Fig. 2 comprises the following parts:

A connecting rod 1 connected with a movable hook L, acts upon a lever 2 rotating upon a stationary pivot 3 provided at its end with a short-circuiting contact 4, the weight'of the lever being balanced by a small weight 5, in order to allow of said lever keeping the inclined positions in which it has been brought. Two remarkably flexible conducting blades 6, 7 are arranged in. such a manner as to frictionally bear simultaneously upon the part 4 when the lever 2 is raised by the end of the lever 8 which may oscillate upon a stationary pivot 9. This lever 8 is made integral with the soft iron armature 10 which passing may be drawn by the electromagnet 11. The

blades 6 and 7 are connected respectively to terminals 6, 7 placed upon a break of the main circuit, and the wire of the winding 11 closes the circuit M N of the'magnetic alarm on which it is switched, Figs. 1 and 2. Two small switches 12, 13, Fig. 2, actuated by the same controlling means may respectively close their circuits and consequently bring the telephone plant in its initial position shown in Fig. 1, by completing annihilating the action of the present device.

The operation of the device is as follows It will be seen in Fig. 2 that when the alarm currentpasses through the magnetic alarm S it also acts upon the electromagnet 11 which tends to draw the soft iron armature 10. On taking the receiver from the hook, the lever L rises together with the connecting rod 1 thus releasing the lever 2 which will rise again being driven by the lever 8 the soft iron armature of which will have been drawn by the electromagnet 11.

The part 4 of lever 2 meets simultaneously both blades 6, 7 which results in the main circuit being closed and the circuit returning momentarily in the normal state shown in Fig. 1. It will be noted that the spring contacts 6 and 7 are long so that the round end of a rod 4 will remain in contact there 'ith for an appreciable time, to permit suilicicnt time to change from signalling current to talking current and prevent disconnection. Consequently the conversation may take place without any hindrance. When the receiver 14 is again suspended on the hook, the mov able lever L as it descends drives the lever 2 by means of the connecting rod 1 with the result of insulating the blades 6, 7 one from the other by the interruption of the main circuit. It will be noted. that the weight of the receiver will be sufficient to disengage the soft iron part in the case of remanence effects tending to retain it.

It will be evident that with a telephene plant arranged as described it will be impos sible to get a connection without being pre- Viously called as, when taking down the re ceiver, the plant being in the position shown in Fig. 2, the equilibrated lever 2 will not be acted upon, and the blades 6, 7 remainin in sulated from each other, the separation in the line results in annihilating the closing of the circuit brought about by the lever L.

Fig. 3 of the appended drawing shows diagrammatically a small device for the realization of my invention by means of a small apparatus completely independent of the telephone properly so called, which may consequently be placed at a great distance from the latter.

Said apparatus is connected by means of a 3 thread cable connected respectively to the three terminals m m m which are substituted for the terminal Min Fig. 1, by twice separating the line as between m m and wa -4n as will be seen in Fig.

It will be understood that by rotating the 'latch shown diagrammatically upon the terminal m Fig. 3, the three terminals m m 122. will be connected and the circuit will thus be brought to the normal state shown in Fig. 1 by annihilating completely the effects of the device hereinafter described.

Said device comprises a coil 15 having two windings 16, 17, the winding 16 consisting for instance of 10.000 turns of 15/100 wire (450 ohms) and the winding 17 of 2.000 turns of 30/100 wire (25 ohms). For the sake of clearness both windings are shown separately in the diagram Fig. 3, but they are in reality wound around the same magnetic core which may draw a soft iron armature 18, placed upon a spring 19 retained by a lever 20. Said lever 19 being able to close a circuit by con necting momentarily together the two flexible blades 22. The connections are made in the following manner:

The terminal m is connected with the blade 21; the blade 22 communicates with the winding 17 both ends of which are connected together by means for instance of a 1 micro farad condenser 23 to meet afterwards the terminal on". The terminal m communicates with terminal 027, by means of winding 16.

The operation in the various cases is as follows:

1st case.-The receiver being taken from the hook the lever L tends to close the metal circuit of the apparatus on the central battery and the alarm relays but there is a break in said circuit between the two blades 21, 22 also constituting retarding means as will be seen in Fig. 3 and consequently the passage of the electric current being interrupted the telephone exchange is not called. It will therefore be seen that the call is rendered impos sible.

2nd case.-The exchange calling, alternating current flows at m, passes through the winding 16 to the condenser C and actuates the magnetic alarm S. Simultaneously, by the action of winding 16 the electromagnet l5 draws its armature 18 thus uniting the blades 21, 22 the momentary insulation of which had made the call impossible in the preceding case. From that instant two states of things may be considered according as the call is answered or not. If the call remains unanswered when it ceases, the lever 19 comes again under the action of the return spring 20, the circuit between the blades 21 and will again be interrupted and the plant will again assume the state shown in Fig. 3. If on the contrary when the alarm calls, the re ceiver is taken down from the hook, the circuit being closed between the blades 21 and 22, owing to the action of the alternating calling current the contact of lever L will produce its whole effect and as is well known, the continuous conversation current will be substituted for the alternating current, the first passing simultaneously in the winding 17 and in the condenser 23 as in Fig. 3, said condenser 23 (1 microfarad) shunteduponthe winding 17 acting to facilitate the passage of the microphonic currents which would be hindered by the self resistance of the electromagnet.

The operation which has just been described with reference to Fig. 3, may be practically executed by means of the small apparatus shown in Figs. 1, 5, 6, 7.

As will be seen in Figs. 1, 5, 6, said apparatus comprises an electromagnet 15 having two windings, a condenser 23 and a plate at of insulating material carrying all the connections as shown in Fig. 7.

The soft iron armature 18 is made integral with a stem 18, Fig. 6, carried upon points between two pivot screws 41 o in order to allow its oscillating freely in front of the cores of the electromagnet 15. To said armature is secured a small carrier at (Fig. 5) up on which is mounted a small half-moon shaped closed tube 6 in which a large drop of mercury 0 has been confined as will be seen in Fig. 5. Two wires 21, 22 wound with platinite are soldered in the tube 7) and insulated as will be seen in Figs. 5 and 6. These wires are rather long and constitute means to delay the breaking of the control circuit while changing from signalling to talking current. Both these wires are respectively connected to flexible wires not represented and arranged so as not to prevent oscillation.

The mode of operation is as follows:

The armature 18, the carrier at and the tube 5 which are made integral are weighted in such a manner that when at rest they are inclined in the position shown in Fig. 5. It will be noted that in this position the mercury not coming in contact with the platinite wires the same are insulated from each other thus producing the separation shown between 21 and 22 in Fig. 3.

The current flowing in the electromagnet, the armature is at the same time drawn by both cores of said magnet and takes a horizontal position, the mercury then moves in its.

tube and contacts simultaneously with both platinite wires thus closing the circuit.

As will be seen in Fig. 7, all the connections designed to make up the diagram shown in Fig. 3 are grouped upon plate 24 The three line wires are connected to the three terminals m m m which are themselves connected to the flexible blades n n n which may be short circuited by means of a key provided to this end with three teeth as will be seen in Fig. 8.

What I claim and desire to secure by Letters Patent of the United States is:

1. In a telephone station, a telephone connected to the incoming line and including a hook to ellect'such connection,-a signal circuit shunted across the line, said incoming line being disconnected on each side of the point of connection of the shunt signal circuit therewith, three connecting points determining such disconnections, an electro magnet having a fine wire winding and a coarse wire winding, the fine wire winding connected between the middle connection and the incoming line, a second normally open circuit line being disconnected on each side of the point of connection of the shunt signal circuit therewith, three connecting points determining such disconnections, an electro magnet having fine and coarse wire windings, the fine wire winding connected between the mi ddle connection and the incoming line, a second normally open circuit connecting the telephone and incoming line and including the coarse wire winding, a condenser shunted across the coarse wire winding, a pivoted armature for the magnet, a mercury contact device carried by the armature to close the second normally open circuit, and means to short circuit the three points at will and permit normal operation of the telephone.

3. In a telephone station, a telephone connected to the incoming line and including a hook to effect such connection, a signal circuit shunted across the line, said incoming line being disconnected on each side of the point of connection of the shunt signal circuit therewith, three connecting points determining such disconnections, an electromagnet having fine and coarse Wire winding, the fine wire winding connected between the middle connection and the incoming line, a second normally open circuit connecting the telephone and incoming line and including the coarse wire winding, a condenser shunted across the coarse winding, a spring retracted lever arranged to close the normally open circuit, an armature for the .magnet on the lever whereby the lever is actuated to close the normally open circuit, and means to connect at will said three connecting points to permitsignals to be sent to line while short-circuiting the electro-magnet.

In testimony that I claim the foregoing as my invention, I have signed my name.

JAMES TIBURCE FELIX 'ooNTI.

connecting the telephone and incoming line I circuiting the electro-magnet.

2. In a telephone station, a telephone connected to the incoming line and including a hook to effect such connection, a signal circuitshunted across the line, said incoming 

